Method and apparatus for producing knit pile fabric

ABSTRACT

A METHOD AND APPARATUS FOR PRODUCING KNIT PILE FABRIC WHEREIN PILE FIBERS ARE FED AS A ROVING OR SILVER BY A FEEDING AND DRAFTING SECTION, DRIVEN BY A VARIABLE SPEED ELECTRIC MOTOR, TO THE MAIN CYLINDER AND DOFFER OF A CARDING HEAD WHICH IN TURN CARDS AND FEEDS THE FIBERS TO THE NEEDLES OF A ROTARY CYLINDER KNITTING MACHINE. THE DRAFTING SECTION MOTOR DRIVE IS INDEPENDENT OF THE HEAD AND MACHINE DRIVE, AND IS CONTROLLABLE AND VARIABLE DURING RUNNING AND/OR SET-UP TO PERMIT GRADUAL SPEED VARIATION AND/OR SPEED SELECTION.

A. W. SCHMIDT Feb. 16, 1971 METHOD AND APPARATUS FOR PRODUCING KNIT PILE FABRIC 6 Sheets-Sheet 1 Original Filed Dec. 20, 1963 FIG.

NVENTOR. ARNOLD W. $00M")? ATTORNEYS Feb. 16, 1971 w I T 3,563,058

METHOD AND APPARATUS FOR PRODUCING KNIT FILE FABRIC 6 Sheets-Sheet 2 Original Filed Dec. 20, 1963 Fla. 2

ii-sa FIG. 7

INVl-INTOR Annou; W. SCHMIDT ATTORNEYS Feb. 16, 1971 A. w. SCHMIDT I METHOD AND APPARATUS FOR PRODUCING KNIT FILE FABRIC Original Filed D60. 20, 1963 6 Sheets-Sheet 5 ARNOLD W gE u-wmt ATTORNEYS Feb. w H IDT METHOD AND APPARATUS FOR PRODUCING KNIT PILE FABRIC Original Filed Dec. 20, 1965 6 Sheets-Sheet 4 IN'VENTfR. ARNOLD W. $CHM lDT ATTORNEYS Feb. 16, 19 71 A. w. SCHMIDT METHOD AND APPARATUS FOR PRODUCING KNIT PILE FABRIC 6 Sheets-Sheet 5 Original Filed Dec. 20, 1963 INVIENTUR. ARNOLD W. Scmmn'r ATTORNEYS Feb. 16, 1971 A. w. SCHMIDT METHOD AND APPARATUS FOR PRODUCING KNIT PILE FABRIC 6 Sheets-Sheet 6 Original Filed Dec. 20, 1963 INVENTOR. RNOLD W. SCHMIDT ea QMJL ATTORNEYS United States Patent Office Patented Feb. 16, 1971 3,563,058 METHOD AND APPARATUS FOR PRODUCING KNIT PILE FABRIC Arnold W. Schmidt, Sarasota, Fla., assignor to Norwood Mills, Inc., Janesville, Wis., a corporation of Delaware Application Dec. 9, 1966, Ser. No. 600,490, now Patent No. 3,501,812, dated Mar. 24, 1970, which is a division of application Ser. No. 332,227, Dec. 20, 1963, now Patent No. 3,299,672, dated Jan. 24, 1967. Divided and this application June 20, 1969, Ser. No. 835,155

The portion of the term of the patent subsequent to Jan. 24, 1984, has been disclaimed Int. Cl. D0411 9/14 US. Cl. 66-9 8 Claims ABSTRACT OF THE DISCLOSURE A method and apparatus for producing knit pile fabric wherein pile fibers are fed as a roving or sliver by a feeding and drafting section, driven by a variable speed electric motor, to the main cylinder and doffer of a carding head which in turn cards and feeds the fibers to the needles of a rotary cylinder knitting machine. The drafting section motor drive is independent of the head and machine drive, and is controllable and variable during running and/ or set-up to permit gradual speed variation and/or speed selection.

This application is a division of my co-pending application Ser. No. 600,490, filed Dec. 9, 1966, now US. Pat. No. 3,501,812 which in turn is a division of my earlier application Ser. No. 332,227, filed Dec. 20, 1963, now U.S. Pat. 3,299,672.

This invention relates to a method and apparatus for producing knit pile fabric of uniform or variable density.

Fur-like or pile fibers generally include a base fabric or back, knitted or woven, and a pile made up of fibers which are interlaced or interlocked with the base fabric so as to be securely held and extended from a surface of the base fabric. Such pile fabrics are well known and usually the base fabric is made of cotton or any other suitable natural or synthetic fiber and the pile is also made from natural or real fur or any one or more of well known synthetic fibers such as nylon, Dacron, the acrylic synthetic fibers such as Orlon, Acrilan, Dynel, rayon, or other well known natural or man-made fibers. Fibers which are commonly used as pile in a fur-like or pile fabric are commercially obtainable in almost any color desired, for example, white, black, gray, brown, yellow, blue, etc.

It is an object of this invention to provide a method and machine for manufacturing a knit pile fabric in which the density of the pile fibers incorporated into the pile fabric may be readily varied, either during set-up of the machine by simply selecting the roving feed-toknitting speed ratio at a speed control, or during the process of knitting a pile fabric by manually or automatically controlling the speed control in timed or synchronized relation to the knitting operation.

Other objects as well as features and advantages of the present invention will become apparent from the accompanying drawings wherein:

FIG. 1 is an elevation showing a new pile fabric knitting machine of the present invention, portions being broken away to illustrate detail.

FIG. 2 is an elevational fragmentary view showing a cylinder or sleeve of knit pile fabric as it is produced by the machine of FIG. 1 before cutting.

FIG. 3 is a fragmentary perspective view of a piece of knit pile fabric after cutting the cylinder along an axial line and flattening it, but prior to clipping or shaving of the pile fibers to a desired uniform length.

FIGS. 4-7 are diagrammatic fragmentary plan views each showing a dilferent piece of the finished fabric of the invention exemplifying four different designs or patterns which have been knitted therein.

FIG. 8 is a side elevation partly in section showing a new carding or pile fiber feeding head of the present invention applied to a conventional circular knitting machine, only a fragment of the conventional knitting machine being shown.

FIG. 9 is a side elevation of the same head shown in FIG. 8 but viewed from the opposite side of the head.

FIG. 10 is a schematic showing of a knitting machine provided with the new carding head for practicing the new method of the present invention.

FIG. 11 is a fragmentary plan view of one set of feed rollers of the upper drawing section of the carding head for feeding one of the rovings to the main cylinder of the carding head.

FIG. 12 is a fragmentary end elevation partly in section of the end rolls of one drawing section.

FIG. 13 is a schematic circuit diagram showing the rheostat control for a variable speed motor one of which is utilized for driving each set of feed rollers of the several drawing or drafting sections which feed the roving to the main cylinder of the carding head.

FIG. 14 is an elevation of a dual unit control mechanism of the present invention for automatically con trolling the dual feed carding head of FIG. 10.

FIG. 15 is a fragmentary enlarged elevation of one unit of the dual unit control mechanism of FIG. 14.

FIG. 16 is a sectional view taken on the line 16-16 of FIG. 15 and rotated degrees to maintain the same scale.

Referring more particularly to the drawings, there is shown a knitting machine such as a circular latch needle machine manufactured by the Wildman Manufacturing Company of Norriston, Pa. The circular latch needle knitting machineis old and 'well known and therefore will not be described in detail, see, for example, the United States patents to Schmidt 2,680,360, Brandt 2,710,- 525 and Moore 1,848,370.

KNITTING MACHINE STRUCTURE Referring to FIGS. 1 and 8-, the so-called head ring 10, which i an annular ring forming part of the frame of the circular knitting machine, is supported above the floor by other parts of the frame 11. The head ring supports a ring gear 12 which is rotatable about a vertical axis in a manner 'well known in the art. The drive for the ring gear 12 is conventional and includes an electric motor M which is connected to ring gear 12 via an electric clutch and brake unit (not shown), belt drive D, bevel gear B and the gear shaft S. The power for driving the main cylinder, doffer and fancy wheel of the carding unit described hereinafter is taken from ring gear 12 by means of a gear 13 (FIG. 8) which meshes with the teeth of ring gear 12. Gear 13 is fixed to the lower end of shaft 14 which is journalled in the bearing housing 16 by rneans of ball bearing races 15. Bearing housing 16 is fixed in the base of carding unit frame 17. Bevel gear 18 is fixed to the upper end of shaft 14 and meshes with a bevel gear 19 fixed on a horizontal drive shaft 20 journalled in frame 17.

A needle cylinder 21 is supported upon and secured by screws to ring gear 12 for rotation therewith. Cylinder 21 carries a circular row of latch needles 22, only a few of which are shown, which are moved vertically by a cam 22 such as disclosed in more detail in the United States patents to Schmidt 2,680,360 or Moore 2,255,078. Since circular knitting machines for knitting pile fabrics 3 are well known, no further description or showing of the knitting mechanism of the machine is necessary.

CARDING HEAD The pile fabric knitting machine is provided with one or more carding heads, only one of which is disclosed herein inasmuch as the description of one carding head will apply also to the others. As shown in FIGS. 1, 8 and 9, each carding head is carried on a frame 17 secured by screws 23 to the frame ring of the knitting machine. The main cylinder or transfer roll 24 of the carding unit is fixed upon a shaft 25 which is journalled at each end in the upright side walls 26 of frame 17. Cylinder 24- is covered with a conventional card clothing generally designated 27 which comprises the usual cotton backing and felt body and wire teeth 28. A convenitional dotfer roll 29 is fixed upon a shaft 30 which is also journalled at each end in radially adjustable arms 31 which are supported upon the side walls 26 of frame 17. Arms 31 are angularly adjusted by a stop screw 32" and held in adjusted position by set screws 32 which pass through arcuate slots 33 in each arm 31 and screw into tapped openings in the side walls 26. Radial or lengthwise adjustment is provided by set screws 32 and slots 33'. The doffer roll also is covered with a conventional card clothing such as the card clothing which covers main cylinder 24. The teeth 28 of the main cylinder or transfer roll 24 preferably just touch the teeth 34 of the doffer roll 29'. The drive for the main cylinder or transfer roll 24 and doifer roll 29 is as follows: gear 35 (FIG. 9) is fixed on one end of shaft 20 and is thus driven off the main ring gear 12 through gear 13, shaft 14, bevel gears 18 and 19 and shaft 20. Gear 35 meshes with a gear 36 which is tfixed on a shaft 37 journalled in the adjacent side wall 26 of frame 17. Gear 36 meshes with a gear 38 fixed on a shaft 3-9 also journalled in the adjacent side wall 26 of the frame 17. Gear 38 meshes with a gear 40 which is fixed on shaft 25 which supports the main cylinder or transfer roll 24. The doffer 29 is driven by means of a gear 41 fixed on shaft 30 which meshes with a gear 42 fixed on shaft 43 journalled in the adjacent side wall 26 of frame 17; Gear 42 in turn is driven by gear 44 fixed on shaft 20.

The carding head of the invention illustrated herein also includes a fancy wheel 46 (FIGS. 8 and 9) fixed on a shaft 48 journalled at its ends in radially adjustable arms 50 attached to arms 52 by set screws 54 which pass through slots 56 in arms 52. Each arm 52 is integral with the arm 31 on the same side of the head and hence moves angularly therewith during such adjustment. Fancy wheel 46 is driven by a V-belt 58 trained around a pulley 60 fixed to shaft 30 and a pulley 62 fixed to shaft 48. Fancy wheel 46 is somewhat similar in construction to the main cylinder 24 and doifer 29 except that the card clothing consists of longer and more widely spaced wires 64 (FIG. 9) which preferably intermesh about /s" with the wires 28 of main cylinder 24. The fancy wheel 46 is substantially completely enclosed by side plates 66 and a peripheral cover 68 which is hinged at 70 to facilitate cleaning.

From the above description and drawings it is evident that the main transfer cylinder 24, doffer roll 29 and fancy wheel 46 are all driven off the ring gear 12 but at different speeds. The aforementioned drive train elements are designed to provide a speed ratio which by way of a preferred example is as follows:

R.p.m. Ring gear 12 i 29 Main cylinder or transfer roll 24 110 Doffer 29 900 Fancy wheel 46 350 This manner of driving rolls 24 and 29 and fancy wheel 46 is preferable but i shown by way of description rather than by way of limitation because any other driving arrangement can be provided as long as the drive for the doffer roll, main cylinder and fancy wheel is independent of the drive for the drawing or drafting section of the carding unit, which will now be described.

DRAWING OR DRAFTING SECTIONS Although the knitting machine of the invention is illustrated herein as having but a single carding unit, it is to be understood that each knitting machine can be provided with a plurality of carding units arranged in angularly spaced relation around frame ring 10. However, it is to be understood that each carding unit is provided with a plurality, that is, two or more drafting or drawing sections. Any suitable drawing or drafting section can be provided for the carding unit but a preferred form is disclosed hereinafter. As shown in simplified form in FIG. 10, two drawing or drafting sections 72 and 74 of the carding unit feed fibers to the main cylinder 24. By way of description, a lower drafting section 72 and an upper drafting section 74 are shown, each of which deliver fibers to the main cylinder 24. Each drawing or drafting section derives these fibers from a separate roving 76' and 78 respectively and acts upon the roving to progressively attenuate, flatten, and widen the same by the drawing action and to preferably convert the roving into a thin, relatively wide web of parallelized fibers uniformly distributed across the width of said web.

Each drafting section is driven independently of the main cylinder 24, preferably by a conventional direct current variable speed motor 80 (FIG. 8) and 82 (FIG. 9) for sections 72 and 74, respectively. However, other suitable types of motors or speed regulatable driving means may also be used. Since the driving arrangement for each drafting section is identical only the drive for the lower drafting section 72 will be described. Referring to FIG. 8, motor 80 drives the lower drafting section 72 through a reduction gearing 84 which, by way of example, has a reduction ratio of about 15 to 1. As shown schematically in FIG. 13, motor 80 is connected into a conventional control unit 86 which includes a rheostat 88 in series with the motor leads 90, 92. Each motor is provided with an identical control unit designated 86 for the right hand motor 80 and 94 for the left hand motor 82 as viewed on the frame 10 in FIG. 1. Rheostat 88 of unit 86 may be manually rotated to vary the speed of motor 80 and rheostat 96 likewise operated to control the speed of motor 82. Each motor 80, 82 and associated reduction gearing and speed control unit are available commercially as a unit and may, for example, comprise the A; Horsepower Motor Speed Control unit sold under the trademark Ratiotrol by Boston Gear Works of Quincy, Mass.

As shown in FIG. 10, each drafting section 72, 74 comprises three pairs of counter-rotating meshing rollers 100, 102, 104, 106, 108 and 110, respectively, fixed to shafts 100, 102', 104, 106, 108 and 110'. Referring again to FIG. 8, shafts 100' and 102' are supported at their ends in a pair of arms 112 pivoted at 114 on frame 17 and held in adjusted position by a set screw 116 which passes through a slot in arm 112 and threads into frame 17. Shafts 104, 106 and shafts 108 and 110' are similarly supported in pairs of arms 118 and 120 respectively. Shafts 100 and 104 are journalled in adjustable bearing blocks 122 which are biased by springs 124 toward shafts 102' and 106' respectively, thereby providing a floating mount of the first and second upper rollers to accommodate variations in roving density. However, as shown in FIG. 12, shaft 108' is journalled in fixed position relative to shaft 110'.

As best shown in FIGS. 10 and 11, feed rollers 100, 102 and 104, 106 of the first and second pairs are formed with helical intermeshing teeth 126 and 128. However, the second pair of rollers are arranged so that their helical teeth are reversed from those of the first set of rollers. The helical intermeshing teeth cause the roving 76 drawn therebetween to be widened as well as flattened due to the helical shape of the teeth pulling the fibers laterally apart. The helical intermeshing teeth also tend to shift the entire web laterally as it emerges from rollers 100', 102, but this effect is corrected by the reversed relationship of the helix angles of the first and second pairs of rollers since the entire web is shifted laterally in the opposite direction as it emerges from the second pair of rollers. The teeth 130 of the third set of rollers 108, 110 are straight rather than helical, and this set feeds the attenuated, flattened and widened roving onto the card clothing 27 of cylinder 24. Preferably rollers 108, 110 are positioned so that they are spaced about of an inch from the ends of wires 28 of main cylinder 24.

As shown in FIG. 8, the feed rollers of drafting section 72 are driven by a .gear train including the drive gear 132 of the reduction gear unit 84 which meshes with a gear 133 fixed on one end of shaft 108. The other end of shaft 108' (FIG. 9) carries a gear 134 which drives via an idler gear 135 a gear 136 fixed on shaft 106'. A gear 137 fixed on the other end of shaft 106' (FIG. 8) drives an idler 138 which in turn drives a gear 139 fixed on shaft 102'. Thus one roller of each pair is driven by the gear train elements while the other roller of each pair is an idler driven by the intermeshing engagement with the driven roller. The second pair of rollers 104, 106 preferably rotate at about 2% times the speed of the first pair of rollers 100 and 102, and the third set of rollers 108, 110 rotate at about 2. /2 times the speed of the second pair of rollers to thereby cause the attenuating action on the roving as it is fed through the drafting section.

Each drafting section 72, 74 also has an apron 140 and 141 respectively adapted to receive the rovings 76 and 78 from their bins or other source of supply thereof and to carry the roving to the first set of feed rollers 100 and 102. As shown in FIGS. 1 and 11, aprons 140 and 141 each support a cross bar 142 and 144 each of which slidably supports a pair of adjustable guide posts 146, 148 respectively. The guide posts are held in adjusted position by set screws threaded in their upper ends which I engage the cross bar. The posts are set so that they are spaced laterally apart slightly less than the average width of the roving. As viewed in FIG. 1, guide posts 146 of the upper drafting section 74 are offset towards the left side of apron 141, while posts 148 of the lower drafting section are offset towards the right side of apron 140. This staggered relationship of the roving guides causes roving 78 to be fed into upper drafting section 74 close to one side of the feed rollers. As shown in FIG. 11, this in turn causes roving 78 to emerge from the third set of rollers 108, 110 with its outer edge 150 adjacent side edge 152 of main cylinder 24. Similarly, roving 76 is fed by the lower drafting section 72 onto main cylinder 24 with its outer edge 154 adjacent the opposite side edge 155 of main cylinder 24. As indicated by the arrows in FIG. 11, the inner edges of rovings 76 and 78 overlap one another.

This staggered relationship of the guides of one drafting section relative to the guides of the next drafting section has been found to be important in preventing a tendency of the rovings to stack or stratify on main cylinder 24 and in promoting the blending of the pile fibers from one roving with the other in the end product. It is to be understood that the staggered relationship of the rovings as they are fed onto the main cylinder is also desirable in the' event that three or more drafting sections are employed with a single carding wheel in accordance with the present invention.

Each drafting section 72, 74 also-has a cylindrical brush 156 (FIGS. 8, 9 and supported at its ends in the upper ends of arms 120 in a friction mount so that the brush normally remains stationary but may be rotated manually as required to present a fresh surface to card clothing 27 and to even up wear on the brush. The bristles of brush 156 just touch the ends of the wires 28 of main cylinder 24 and assist in spreading and smoothing the fibers just after they have been picked up by the main cylinder from each drafting section.

AUTOMATIC CONTROL MECHANISM control mechanism is illustrated in FIGS. 14-16 wherein an electro-mechanical type control unit 160 is shown for controlling the previously described dual feed carding head of the invention. Control unit 160 comprises an identical pair of stepping rheostat control mechanisms 162 and 164 enclosed in a common housing, unit 162 being electrically connected to motor 80 and unit 164 being electrically connected to motor 82.

Control mechanism 162 is shown in detail in FIGS. 15 and 16, and since this mechanism is identical to control mechanism 164 a description of it will suffice for both. Control mechanism 162 includes a conventional rheostat motor speed control unit 166 identical to units 86 and 94 described previously except that the finger knob 171 (FIG. 1) on the end of the rheostat armature shaft 172 is replaced by a pair of ratchet wheels 168 and fixed to shaft 172. Wheel 168 is driven in a counterclockwise direction as viewed in FIG. 15 by a pawl 174 fixed on a post 176 which in turn is pivotally carried by an arm 178 pivoted at one end on shaft 172 and disposed between ratchet wheels 168 and 170. The outer end of arm 178 carries a plate 180 which depends therefrom and supports a post 182 connected by a link 184 to the armature 186 of a conventional solenoid 188. A tension spring 190 is connected at one end to a pivot pin 192 which interconnects link 184 and armature 186. Spring 190 is connected at its other end to an arm 194 affixed to a bracket 196 mounted on unit 166. The limit of pivotal movement of arm 178 in a counterclockwise direction is determined by a screw 198 threaded into bracket 196. Another screw 200' is threaded into a bracket 202 also fixed to unit 166 and provides an adjustable stop for limiting pivotal movement of arm 178 in a clockwise direction as viewed in FIG. 15.

The outer ratchet wheel 168 is normally held against reverse rotation by a detent comprising a spring arm 204 secured at one end to bracket 196 and adapted to engage the teeth 206 of ratchet 168 at its free end. Similarly, reverse rotation of ratchet 170 is normally prevented by a spring arm 208 secured at one end to bracket 202 and adapted at its free end to engage the teeth 210 of ratchet 170. Arm 178 has a pair of wings 212 and 214 which carry screws 216 and 218 respectively. Screw 216 is adjusted to engage detent 204 as arm 178 approaches the counterclockwise limit of its travel, while screw 218 is adapted to engage detent 208 when arm 178 approaches the clockwise limit of its travel.

Pawl 174 is biased into engagement with teeth 206 of ratchet 168 by a tension spring 220. Spring 220 is connected at one end to a post 222 which is fixed to the outer end of an adjusting screw 224 threaded into the outer end of arm 178. The other end of spring 220 is connected to the bent-up end of an arm 226 which extends through post 176 and is fixed thereto. Post 176 carries another pawl 228 which is disposed adjacent teeth 210 of the lower ratchet 170, pawl 228 being held clear of teeth 210 by spring 220 when pawl 174 is working against the upper ratchet 168. 3

A pair of reversing dogs 2.30 and 232 are secured to the outer surface of ratchet 168 by screws 234 which are threadably received in one of ten threaded holes 236 pro-' vided at equally spaced angular intervals around ratchet 168.

The solenoid 188 of unit 162 and the corresponding solenoid of unit 164 may be energized by any suitable timing device. However for ease of synchronization it is preferred to mount one or more microswitches 237 (FIG. 8) adjacent ring gear 12 or other rotating part of the knitting machine, and to mount a switch-actuating arm 238 on the rotating part in a position to strike the microswitch once during revolution of the rotating part. The microswitch is connected as an on-off switch in a conventional solenoid energizing circuit (not shown). By providing two or more actuating arms 238 equally spaced around the rotating part, the number of solenid-actuating impulses per revolution of the rotating part can be increased as desired to thereby increase the speed of rotation of the ratchet wheels 168, 170.

In operation, solenoid 188 is energized to retract armature 186 which, via link 184, pulls arm 178 in a clockwise direction as viewed in FIG. 15. As arm 178 begins to move clockwise, screw 216 disengages detent 204, allowing it to seat between teeth 206 of ratchet 168 to prevent reverse rotation thereof as pawl 174 is dragged clockwise back over a tooth and then engages behind the next tooth. Just before arm 178 strikes screw 200 in its clockwise stroke, screw 218 strikes detent 208 to disengage its free end from a tooth 210 of lower ratchet 170.

Upon de-energization of solenoid 188, spring 190- pulls armature 186 outwardly and, via link 184, pulls arm 178 in a counterclockwise direction, thereby rotating ratchets 168 and 170 one notch in a counterclockwise direction until arm 178 strikes limit screw 198. Screw 218 is adjusted to disengage detent 208 during the counterclockwise stroke of arm 178 just after the peak of a tooth 210' has passed under the free end of detent arm 208. The free end of detent 208 then rides down the back of this tooth until ratchet 170 has been rotated one notch, whereupon detent 208 strikes the leading edge of the next tooth at the same time that arm 178 strikes stop 198. Detent 208 thus serves at this time as a positive stop to prevent overshooting of the ratchets as they are rotated notch by notch in a clockwise direction.

The above sequence is repeated until dog 230 rotates into engagement with arm 226 and pivots this arm to the other side of a center line drawn through the axis of post 176 and post 222, whereupon spring 220 exerts a clockwise moment on arm 226 to rotate post 176 until the pawl 228 is pivoted into engagement with the lower ratchet 17 0 and pawl 174 is simultaneously retracted. A clockwise stroke of arm 178 now causes ratchets 168, 170 to rotate clockwise one notch, and the counterclockwise stroke of arm 178 is the return stroke for pawl 228. Ratchets 168 and 170 are thus rotated clockwise one notch at a time by successive clockwise strokes of arm 178 until the other reversing dog 232 strikes arm 226 and pivots it past its overcenter position, whereupon spring 220 exerts a counterclockwise moment to return pawl 174 to the engaged position and to hold pawl 228 disengaged.

The solenoid of control mechanism 164 for motor 82 is also connected in the microswitch circuit of control mechanism 162 so that control mechanisms 162 and 1 6-4 operate in unison. One rheostat of unit 160 is wired so that clockwise rotation thereof increases the speed of the associated motor, while the rheostat of the other unit is wired so that clockwise rotation thereof decreases the speed of the motor connected to the latter unit. Normally a 180 out of phase relationship is preferred so that the speed of one motor reaches its maximum when the other motor reaches its minimum, and vice versa, the sum of the individual speeds always remaining constant. Since the rate at which rovings 76 and 78 are fed to the main cylinder 24 varies directly with the speed of motors 80 and 82 respectively, the rate of feed of roving 76 is at its maximum when the rate of feed of roving 78 is at its minimum, and vice versa. Hence the sum of the rates of feed will also remain constant, thereby causing the total quantity of fibers delivered by the drafting sections to the main cylinder 24, doffer 29 and needles 22 per unit of time to remain substantially uniform. In this manner the number of pile fibers in each pile element or bundle knitted into the base yarn remains substantially constant, although the quantity of fibers derived respectively from roving 76 and roving 78 varies continuously as a function of the rate of roving feed, the speed of needle cylinder 21 being kept constant.

METHOD AND MODE OF OPERATING MACHINE TO PRODUCE BLENDED, PATTERNED OR FUR- LIKE KNITTED PILE FABRIC With the above-described pile fabric knitting machine of the present invention, it is now possible to produce a variety of novel knit pile fabrics as exemplified by the four different fabrics illustrated schematically in FIGS. 4, 5, 6 and 7. The fabric 250 shown in FIG. 4 is a knit pile fabric made to resemble a natural mink pelt but otherwise is somewhat similar in structure to that illustrated in the US patent to Moore 1,791,741 when greatly enlarged and dissected. However, instead of the individual fibers of the pile elements all having the same physical characteristics, each pile element is made up of a substantially constant number N of fibers including X number of fibers of one color and Y number of fibers of another color corresponding, for example, to the two basic colors found in the fur of the animal which is being simulated.

By way of example, fabric 250 is made up of a row 252 containing a predominance of brown fibers in each pile element adjacent to a row 254 containing a predominance of gray fibers in each pile element. Rows 252 and 254 extend coursewise of the fabric (circumferentially of knitting cylinder 21 as the fabric is being knit) and alternate with respect to one another in the direction of the wales of the fabric. It is to be noted that the brown rows or stripes 252 merge very gradually into the adjacent gray stripes 254, and vice versa, taken in the direction of the wales of the fabric in the same manner that the brown and gray stripes in a mink pelt gradually blend into one another. Thus in appearance fabric 250 is a very close approximation of the natural mink fur.

To manufacture the fur-like fabric 250 of the present invention, the previously described dual feed carding head having the upper and lower drafting sections 74 and 72 is employed. A roving 76 of gray fibers is fed through guide posts 148 of the lower drafting section 72 and between the three pairs of feed rollers, following the aforementioned staggered or offset set-up procedure. A roving 78 of brown fibers is similarly fed into the upper drafting section 74. The base strand or yarn 260 (FIG. 1) is then fed in the usual manner through the conventional guides and tube 262 and threaded into the circular row of latch needles 22 as is well known in the art. Once the roving and yarn set-up is completed, the control mechanism is adjusted to produce the desired stripe width, e.g., the dimension taken in the direction of the wales of the fabric between the center line of the brown stripe 252 to the center line of the adjacent gray stripe 254. This is determined by the angular spacing of reversing dogs 230 and 232, with the speed of rotation of the knitting cylinder 21 taken as the constant reference point. For example, assume that the machine is set up to knit 29 courses of base fabric per minute and that the stripe width is to be 87 courses or about three inches. For this size of stripe the reversing dogs 230 and 232 are spaced angularly apart on ratchet 168 so that it requires three minutes from the time one dog leaves arm 226 until the other dogstrikes arm 226 to reverse the rotation of the rheostat.

After the above set-up is completed, motor M is connected to drive knitting cylinder 21 at a constant rotational speed, thereby causing main cylinder 24, doflFer 29 and fancy wheel 46 to rotate at the aforementioned constant speed ratio. However, the rate of feed of rovings 76 and 78 is controlled independently of the other elements of the carding head by control unit 160. Assume that rheostat unit 162 controls the rate of feed of gray roving 76 and that it is at the maximum speed setting, and that rheostat unit 164 controlling the rate of speed of brown roving 78 is at the minimum speed setting. The gray roving 76 will thus be fed at full speed through the lower drafting section 72 onto the card clothing 27 of main cylinder 24 which carries it clockwise (FIG. 10) first past brush 15.6 and then up past the upper drafting section 74 where brown roving 78 is being fed at slow speed onto the periphery of cylinder 24. Due to the staggered relation of rovings 76 and 78, the brown roving will be laid over the gray roving 76 with a slight overlap as indicated in FIG. 11, thereby covering substantially all of the transverse width of cylinder 24 with gray and brown fibers. The gray and brown fibers are then carried under brush 156 of drafting section 78 and onward to fancy wheel 46.

It is to be noted at this point that the fancy wheel wires 64 intermesh about one-eighth inchwith the wires 28 of the carding wheel (FIG. 9). Wheel 46 does not function as a transfer roll but rather operates to raise the fibers being carried by the card clothing 27 of main cylinder 24 from the bottom of the clothing up to the outer surface of the clothing for presentation to dolfer 29, thereby promoting a greater transfer of fibers from the main cylinder 24 to the doffer 29. The pile density of the fabrics hereunder consideration normally ranges from about 1 pound to about 5 pounds per square yard. When making the lighter density fabrics, fancy wheel 46 may be omitted but its use is recommended when making the greater density fabrics and high rates of roving feed are encountered. Wheel 46 also is beneficial in causing some degree of intermixing of the gray and brown fibers as they are being carried on the main cylinder 22.

The fibers then reach the tangential contact point of cylinder 24 with dotfer 29, which is rotating counterclockwise as viewed in FIG. at about 5 times the speed of cylinder 24. The wires 34 of doifer 29 preferably just touch wires 28 of main cylinder 24 and pick up the fibers which have been raised to the surface of the clothing 27, plus whatever fibers are entangled with the surface fibers. The balance of the fibers continue on around with cylinder 24 and become mixed with the fibers being added at drafting sections 72 and 74. The transfer of fibers to doffer 29 causes some further mixing of the brown and gray fibers. The fibers are then carried counterclockwise on doffer 29 past the path of travel of needles 22 which are elevated as they approach dotfer 29 so that the upper hook end of the needle penetrates the card clothing of the doifer. Needles 22 enter at one edge of the dofier clothing and rake across the clothing with their latches 264 open, as shown in FIGS. 8 and 10. During this traverse, each needle picks up a bundle of pile fibers which represents an average sampling of the relative amounts of gray and brown fibers then present on the doffer.

Thus, in the example given where initially the maximum amount of gray fibers and the minimum amount of brown fibers are being fed to the main cylinder, approximately these same proportions of gray and brown fibers will be present in the bundle of fibers on the needle, allowing for a slight lag due to the transfer time from the drafting section to the needle. There is also a further intermingling of gray and brown fibers as they are accumulated in a bundle on each needle during its traverse of the doifer. This intermixing within each bundle is further promoted by the action of the needle as it knits the pile fibers into the base fabric to form the cylindrical sleeve 266 (FIG. 2) in the machine.

The resulting color of each bundle visible to the naked eye has been found to generally follow the principles of color blending of paints; that is, if a bundle contains 50 percent of gray fibers and 50 percent of brown fibers it will appear to be an intermediate color such as that re-. sulting from mixing an equal quantity of gray and brown pigment. Hence the physical intermixture of the fibers 10 which takes place on the carding head and in knitting the pile into the base fabric is herein termed a blending action, although under microscopic enlargement the individual or discrete physical characteristics which distinguish the fibers of one roving from the other is always identifiable.

Continuing with the above example, the rate of feed of the gray roving 76 is gradually diminished under the control of motor 80 as rheostat unit 162 rotates step by step clockwise, while simultaneously the speed of motor 82 and consequently the rate of feed of brown roving 78 is gradually increased under the control of unit 164. Hence, the first few courses knitted in the sleeve 262 will be predominantly gray. As the amount of brown fibers increase and the amount of gray fibers diminish, the next courses knit by the machine will become more brown in hue, this transition continuing until the maximum brown and minimum gray is being fed by the carding head to the needles, whereupon several courses of predominantly brown knit pile fabric are produced. When the control units 162, 164 simultaneously reverse, the percent of brown fibers will again start to diminish and the gray fibers begin to increase from their minimum, thereby producing a gradual return to courses of intermediate gray-brown hues. When the gray fibers predominate once more, the center of the next gray stripe 254 will have been produced.

The above sequence is automatically repeated until the entire sleeve 266 is knit, and then the machine is shut down automatically or manually and the sleeve removed from the machine. Sleeve 266 is then cut along an axial line 268 (FIG. 2) and laid open for subsequent treatment, including shaving along a line 270 as illustrated in FIG. 3, followed by subsequent backing and polishing steps as conventionally practiced in the manufacture of ordinary pile fabrics.

Although the above example dealt with only one variable, e.g., the color of the pile fibers knitted into the base fabric, it is to be understood that pile fibers differing with respect to one or more other physical characteristics, such as the denier of the fibers, average length of the fibers or the material from which the fiber is made, may be intermixed in accordance with the present invention. Thus fibers of two colors and two deniers, for example, may be blended in varying amounts to produce a striped pattern which also alternates as to the coarseness of the pile.

Although a dual feed carding head is illustrated herein, it is also possible to arrange three or more drafting sections around the carding cylinder 24, a larger cylinder being required as the number of drafting sections is increased. This enables a greater number of separate and different rovings to be employed in making a blended knit pile fabric.

With the above variations in mind, it will be understood that the number of possible new products which can be manufactured employing the method and/or machine of the present invention is almost limitless. Another feature is that a skilled operator, by manipulating the manual rheostat controls 86 and 94 as illustrated in FIG. 1, can paint various patterns and designs by varying the blend of the fibers knitted into the fabric as desired. Once a pleasing pattern is obtained, the control sequence required can be computed from the finished fabric and the sequence translated to computer tape for operating an automated production line.

Moreover, the blending carding head of the present invention is advantageous even when two different rovings are fed to the carding head at equal and constant rates of feed. The end product resulting from this method and mode of operating the machine is illustrated by the knitted pile fabric 272 shown schematically in FIG. 7. Fabric 272 has an improved blend of the two fibers over that hitherto obtainable by feeding two rovings of differently colored fiber into a single drafting section. The two different fibers are more thoroughly intermixed and less readily recognizable to the naked eye which, in the case of a two-color Iblend, means a more solid shade of an intermediate hue.

A further example of the product possibilities obtainable with a carding head having a plurality of individually controllable drafting sections is exemplified by the checkerboard patterns produced in the fabrics 274 and 276 illustrated respectively in FIGS. and 6. In order to produce patterns of this nature, a suitable phase control of the two motors is provided by microswitches arranged in the manner of the timing switch or switches previously described for ratchet rheostat unit 160 or by other conventional timer controls. With such a control the motors 80 and 82 are alternately turned on and off to first cause a feed solely of one roving followed by a feed solely of the other roving in an alternating sequence within each course of the sleeve 2 66 as it is knit. Thus in the first row 278 of fabric 274 (FIG. 5) several courses of fibers 280 from one roving alternate coursewise with several courses of fibers 282 from the other roving. After the number of courses making up the first row 278 have been knit, a suitable phase shift control or other device causes the roving feed to continue for a double interval and thereafter the original sequence resumes, thereby knitting the second row 284 of fabric 274 wherein the fibers 282 are adjacent fibers 280 of the row 278 and fibers 280 of the row 284 are adjacent fibers 28 2 of row 278.

As used herein, the term physical characteristics when referring to the properties of the individual fibers, either natural or synthetic or a mixture of the same, making up each pile element or bundle in the fabric is used generically to encompass both visually identifiable properties such as color, length, denier and size as well as other physical properties identifiable only by test or analysis, such as strength. It is also to be understood that the individual rovings 76, 78 may be made up of mixtures of fibers, either natural or synthetic, having different characteristics and such mi-xed rovings fed separately onto the carding means in the practice of the present invention.

Another important variable which is controllable in a predetermined manner in the practice of the present invention is the density of the pile fibers within the fabric. Although previous examples have dealt with varying the blend of pile fibers while making a knit pile fabric having a pile of substantially uniform density throughout the fabric, it is to be understood that the density of the pile can be readily varied walewise and/ or coursewise of the fabric to produce pattern effects or to simulate the manner in which the density of animal hair varies in a natural fur pelt. For example, the hair on the back of the fur-bearing animal being simulated may be denser than that on the belly. Therefore to produce an accurate reproduction of such fur in a knit pile fabric in accordance with the present invention, the combined rate of feed of the separate rovings 76 and 78 is varied as the base fabric is being knit as a function of the portions of the sleeve 266 corresponding to the back and belly in such a manner as to simulate this natural condition. This in turn causes the total number of pile fibers per bundle to vary as the fabric is being knit. In making fabric 250 of FIG. 4, this density variable may be superimposed on the color variable which is controlled to produce the alternating brown and gray striped effect. However, if desired the density or total number of pile fibers per bundle may be the sole variable knit into the fabric.

One way of achieving variable density of the fabric pile is by manual operation of rheostat control units 86 and 94 in such a manner that the combined rate of feed of rovings 76 and 78 is varied to increase or decrease the density of the pile fibers as required to produce the desired density variation in the pile of the fabric as it is being knit. For example, units 86 and 94 may both be rotated at the same time to increase the speed of motors 80 and 82 at the same rate. This will maintain a constant ratio of fibers derived from the respective rovings, such 12 as 50 percent from roving 76 and 50 percent from roving 78, while increasing the total number of fibers delivered to each needle and hence the total number of fibers 7 per bundle element.

If it is desired to combine a striping effect with a progressive stepped variation in pile density, then the two controls 86 and 94 may be operated in the 180 out-ofphase relationship (i.e., as the speed of one motor increases the speed of the other correspondingly decreases) previously described through a progression of range. Thus, in the first range control 86 may be rotated to vary the speed of motor from say 0 percent to 10 percent of its maximum speed while control 94 is operated to decrease the speed of motor 82 from 10 percent down to 0 percent of its maximum speed, and vice versa. The resulting pile density will then be equal to the number of fibers fed by one drafting section 72 or 74 operating at 10 percent of maximum speed. Then the range may be shifted upwardly so that controls 86 and 94 are similarly operated to run motors 80 and 82 between 10 percent and 20 percent of their maximum speed. This will cause the same striping effect due to the 180 out-of-phase variation between the two controls 86 and 94, but the pile density will be increased and equal to that produced by one drafting section operating at 30 percent of its maximum speed. This progression can be continued until the motors are being operated 180 out-of-phase between 90 percent and percent of their maximum speeds. When so operating in the ranges over 50 percent of maximum speed, the resulting pile density will be greater than that produced in the earlier described example wherein each motor varied between its minimum and maximum speeds in a out-off-phase relationship to produce a uniform pile density equal to the maximum output of one drafting section, e.g., 50 percent of total pile delivering capacity of the dual feed carding head.

Instead of being manually operated the aforementioned additional series rheostat may be controlled by a third stepping ratchet mechanism identical to the previously described automatic control unit 162. This third automatic control unit can be combined with the two manual units 86 and 94 or with the two automatic units 162 and 164. If the third automatic control is set to rotate between minimum and maximum settings and then back again at a slower rate than the rotation of units 86 and 94, the density of the blend will likewise alternate between maximum and minimum at a slower rate than the striping variation. By a suitable adjustment of the striping controls 86 and 94 relative to the density control, it is possible to produce several stripes of heavy density and then several stripes of less density to thereby simulate the back and belly portions, respectively, of a natural fur pelt.

It is also possible to produce a pelting action without a striping effect wherein the density of the pile is varied to simulate the thick fur on the back of a solid color animal and then the thinner fur on the belly. T o achieve this effect it is only necessary to operate the two controls 86 and 94 in unison between a minimum of say 30 percent of full speed on each control and a maximum of 70 percent of full speed on each control while the machine is knitting a portion of the sleeve corresponding to the center of the belly to the center of the back. Then controls 86 and 94 are rotated in unison from the aforesaid maximum back to the aforesaid minimum speed settings as the machine knits the portion of the fabric corresponding to the other half of the pelt. By so maintaining a constant feed ratio between two differently colored rovings while varying their combined feed rate, a pelt of varying density but of one blended color will be knit. Of course, two rovings of the same color may also be fed by the two drafting sections 72 and 74 in the above manner when producing a solid color pelt, or only one drafting section 72 need be used to feed one suitably colored roving. In the latter case, the rate of feed of the sole roving is controlled by using just the one control 86 to 13 vary the density of the pile fiber bundles being knit into the fabric.

To produce a combined color striping and pelting action by manual control, two differently colored rovings 76 and 78 are fed via drafting sections 72 and 74. As an example, when the belly portion is being knit, control 86 is first increased from to 20 percent of full speed while control 94 is decreased from 20 to 10 percent of full speed, and vice versa, for a given period of time corre sponding to several courses of fabric. Then, in the next successive time periods, the ranges are gradually increased to between 11 to 22 percent, 12 to 24 percent, 13 to 26 percent and so on, of full speed for each control while still maintaining the 180 out-of-phase manipulation. This produces a gradual increase in density while maintaining the color pattern, e.g., stripe width and color variation from stripe to stripe. When the back portion is reached the two controls will then, for example, be manipulated between 50 to 100 percent of their respective full speeds, thereby producing a density of pile in the fabric five times that knit at the start of the belly portion. The sequence is then reversed until the belly portion (the opposite coursewise edge of the finished fabric) is reached.

It is also possible to have one color or other characteristic of the fiber predominate over another color or characteristic throughout the fabric and still obtain the striped effect. For example, the gray fibers may predominate throughout the fabric by controlling the rate of feed of gray roving so that it ranges between predetermined limits, say from 70 to 80 percent of the fiber content of the fabric, while the brown fibers are fed at a rate such that they range between 20 and 30 percent of the fiber content. When the relative amounts of these two colors vary in the 180 out-of-phase sequence previously described, a striped effect results with the gray hue predominating.

A third drafting section similar to and in addition to drafting sections 72 and 74 may be used to feed a third roving made up of fiber guard hairs to the carding head at a rate correlated with the feed of rovings 76 and 78. This will result in extra-long, heavier denier pile fibers 255 (FIG. 4) being scattered throughout the fabric 250 in a predetermined arrangement to simulate the way in which such guard hairs occur in the pelt of a fur-bearing animal. The third drafting section may be omitted and the fiber guard hairs mixed into the rovings 76 and/or 78 prior to feeding these rovings to their respective drafting sections 72 and 74.

It is also to be understood that various control systems other than the manual system shown in conjunction with FIG. 1 and the electro-mechanical stepping rheostat type shown in conjunction with FIGS. 1416 may be employed to control the machine of the invention in accordance with the method of the invention. For example, the rheostat associated with each motor of the respective drafting or drawing section may be controlled by a control mechanism wherein a cam or cams control the operation of servo-motors which in turn control rotation of the rheostat armatures. In this manner, a particular fabric design representing the combination of one or more variables may be produced by providing suitably designed cams to reproduce this fabric. By providing a stock of such cams, one for each different pattern, set-up time can be considerably reduced and uniformity of product consistently obtained. Such servo-motors are also readily adapted to computer control where the design information may be recorded on computer tapes for use in a high production, completely automated set-up.

The manner in which the needles 22 knit the pile bundles or elements into the base yarn as the base fabric is knit is well understood in the art and set forth in more detail in the U8. Schmidt Pat. No. 2,630,619 and the US. Moore Pat. No. 2,255,078.

What is claimed is:

1. Apparatus for making knit pile fabric comprising a carding head including transfer roll means having card clothing carried aound the periphery thereof and a doffer disposed in fiber transfer relation with said transfer roll means, means for feeding a roving comprising a drafting section having a plurality of sets of drawing rollers adapted to feed a roving of pile fibers therebetween toward the clothing of said transfer roll, said roving feeding means having an output end disposed for feeding the roving of pile fibers onto the clothing of said transfer roll means, a variable speed electric motor operably connected to and for driving said roving feeding means, variable impedance means for controlling the speed of said motor to vary the rate at which roving is fed through said roving feeding means independently of the rotational speed of said transfer roll means and doffer, means for knitting a base fabric including needle means for removing the carded fibers from said doffer and incorporating said removed fibers into the base fabric as it is being knitted to thereby produce the knit pile fabric and drive means separate from said motor for operating said carding head and knitting means at a predetermined constant speed, said variable impedance means including a control member operable during the operation of said knitting means and when the knitting means is shut down for varying the impedance of said impedance means and means for operating said control member such that the motor is operated through a cycle of speed variations during operation of said knitting means correlated in a predetermined manner with the speed of said knitting means.

2. A method of making a knit pile fabric comprising the steps of:

(1) feeding a roving of pile fiber into a carding area,

(2) carding the fibers in the carding area at a substantially uniform speed,

(3) regulating the rate of feed of said roving to said carding area during said feeding step to thereby gradually vary the number of fibers in the carding area during said carding step as a function of time in a predetermined manner,

(4) removing the carded fibers from the carding area by causing knitting needles to rake the carding area at a uniform knitting speed and (5) incorporating the removed fibers in a base fabric as it is being knitted by causing said needles with the removed fibers thereon to knit a base yarn at said uniform knitting speed to thereby produce a knit pile fabric having a varying density of the pile fibers derived from said roving.

3. In a pile fabric knitting machine having a circular row of knitting needles operable at a constant speed to knit a base fabric, the improvement comprising pile fiber feeding means including a main cylinder having card clothing carried around the periphery thereof, a doffer roll disposed in fiber receiving transfer relation to said main cylinder and positioned to be raked by said needles to thereby feed fibers to the needles of said knitting machine, a roving feeder having an output end disposed for feeding roving onto the clothing of said main cylinder, first drive means for rotating said main cylinder and doffer roll at a predetermined constant speed, second drive means for said roving feeder including a variable speed electric motor operably connected for driving said roving feeder and control means adjustable either during operation or shut-down of said machine for controlling the speed of said motor through a cycle of speed variations during operation of said machine to thereby vary the rate at which roving is fed through said roving feeder independently of the rotational speed of said main cylinder and doffer roll and the knitting speed of said needles.

4. In a pile fabric knitting machine having a circular row of knitting needles operable at a constant speed to knit a base fabric and apparatus for feeding pile fibers to said needles comprising a carding head mounted on said knitting machine including a carding transfer roll and a doffer disposed for receiving fibers from said transfer roll and positioned to be raked by said needles, first drive means for driving said needles, said transfer roll and said dofier at a constant speed, a drafting section for respectively drafting and feeding a pile fiber roving to said trans fer roll, said drafting section comprising at least two pairs of rollers, the rollers of each pair being counter-rotating and adapted to feed the roving therebetween and one of said pairs of rollers being spaced from the other of said pairs of rollers in the direction of roving feed, said one pair of said rollers being disposed adjacent said transfer roll, the improvement which comprises second drive means separate from said first drive means including a variable speed electric motor mounted on said drafting section, a gear train drivingly connecting said motor to at least one roller of each of said pairs of rollers and providing a fixed speed ratio between said pairs of rollers whereby said one pair of rollers is driven at a higher speed than said other pair, and programmable control means for controlling the speed of said motor during operation of said machine throughout a range between zero and maximum speed in a predetermined manner correlated with the speed of said needles.

5. The apparatus as set forth in claim 4 wherein said drafting section includes a third pair of counter-rotating rollers adapted to feed the roving therebetween and spaced from said other pair of rollers on the side thereof remote from said one pair of rollers, each of said pairs of rollers having loosely intermeshed teeth, said one, other and third pairs of rollers being driven at a constant ratio relative to one another of approximately 5:2 /2:1 respectively.

6. In a pile fabric knitting machine having a circular row of knitting needles operable at a constant speed to knit a base fabric and apparatus for feeding pile fibers to said needles comprising a carding head including a main cylinder having card clothing carried around the periphery thereof, a doffer disposed in fiber receiving relation to said main cylinder and positioned to be raked by said needles, and first drive means for revolving said needles and for rotating said main cylinder and dolfer at a predetermined constant speed relative to the rate of travel of said needles, the improvement which comprises a roving feeder having an output end disposed for feeding a roving onto the clothing of said main cylinder, second drive means separate from said first drive means and including an electric motor gradually variable in speed and operably connected for driving said roving feeder at gradually selectable speeds and pattern means for cyclically controlling the speed of said second drive means during operation of said first drive means to vary in a predetermined manner the rate at which roving is fed through said roving feeder independently of the rotational speed of said main cylinder, doffer and needles.

7. In a pile fabric knitting machine having a circular row of knitting needles operable to knit a base fabric and a carding head for carding and feeding pile fibers to said knitting machine, said carding head comprising a main cylinder and a dotfer roll disposed in fiber transfer relation to said main cylinder and positioned to feed the pile fibers to said needles of said knitting machine, and a paired roller roving feeder having an output end disposed for feeding pile fiber roving onto said main cylinder, the improvement comprising means including a first electric motor for driving said main cylinder and doffer roll at a predetermined constant speed, means including a second speed controllable electric motor for driving said roving feeder at selected speeds and independently of said main cylinder and doffer, and control means connected to said second motor and adjustable either during operation of said machine or when the same is shut down for operating said second motor through a cycle of speed variations during operation of said machine correlated in a predetermined manner with the knitting operation of said needles.

8. The knitting machine as set forth in claim 7 wherein said roving feeder comprises a roving drafting section for drafting and feeding the pile fiber roving to said main cylinder, said drafting section comprising at least first and second pairs of feed rollers, each of said rollers having teeth about the periphery thereof loosely intermeshed with the teeth of the associated roller of the same pair of rollers such that the rollers of each pair counter-rotate relative to one another and are adapted to feed the roving therebetween, said first pair of rollers being disposed adjacent said main cylinder and said second pair of rollers being spaced from said first pair of rollers on the side thereof remote from said main cylinder, said means for driving said roving feeder including a drive train drivingly connecting said second motor to at least one roller of each of said first and second pairs of rollers to operate said first set of rollers with a surface speed higher than that of said second pair of rollers to thereby draft the roving as it is fed by said drafting section to said main cylinder.

References Cited UNITED STATES PATENTS 1,759,260 5/1930 Hoffmann 19145.7 1,848,370 3/1932 Moore 669(B) 2,773,371 12/1956 Moore 669(B) 2,971,357 2/1961 Hill 669(B) 2,993,351 7/1961 Wheelock 669(B) 3,122,904 3/1964 Brandt 669(B) 3,188,834 6/1965 Radtke 669(B) FOREIGN PATENTS 27,637 1912 Great Britain 19- 258 ROBERT R. MACKEY, Primary Examiner US. Cl. X.R. 19105, 258 

